Hello Dillon Varone,
Commit 4465dd0e41e8 ("drm/amd/display: Refactor SubVP cursor limiting
logic") from Apr 1, 2025 (linux-next), leads to the following Smatch
static checker warning:
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c:336
dc_stream_program_cursor_attributes()
error: we previously assumed 'stream' could be null (see line 334)
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c
327 bool dc_stream_program_cursor_attributes(
328 struct dc_stream_state *stream,
329 const struct dc_cursor_attributes *attributes)
330 {
331 struct dc *dc;
332 bool reset_idle_optimizations = false;
333
334 dc = stream ? stream->ctx->dc : NULL;
^^^^^^
The old code assumed stream could be NULL.
335
--> 336 if (dc_stream_set_cursor_attributes(stream, attributes)) {
^^^^^^
The refactor added an unchecked dereference.
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c
313 bool dc_stream_set_cursor_attributes(
314 struct dc_stream_state *stream,
315 const struct dc_cursor_attributes *attributes)
316 {
317 bool result = false;
318
319 if (dc_stream_check_cursor_attributes(stream,
stream->ctx->dc->current_state, attributes)) {
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Here. This function used to check for if stream as NULL and return false
at the start. Probably we should add that back.
320 stream->cursor_attributes = *attributes;
321 result = true;
322 }
323
324 return result;
325 }
regards,
dan carpenter
